Separator membranes for lithium ion batteries and related methods

ABSTRACT

A ceramic-coated battery separator having a microporous polyolefin membrane and a ceramic coating on at least one surface of the microporous polyolefin membrane, wherein the ceramic-coated separator exhibits a strain shrinkage of 0% at temperatures greater than or equal to 120 degrees Celsius is provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional application to U.S. application Ser.No. 13/960,924, filed Aug. 7, 2013; which claims priority to and thebenefit of U.S. provisional patent application Ser. No. 61/680,550 filedAug. 7, 2012 which is fully incorporated by reference herein.

FIELD OF THE INVENTION

The present invention is directed to improved, new or modifiedmembranes, separators, and/or related methods. In accordance with atleast certain embodiments, the present invention is directed toimproved, new or modified nonporous, porous, or microporous batteryseparator membranes or separators and/or related methods of manufactureand/or use of such membranes or separators. In accordance with at leastselected embodiments, the present invention is directed to improved, newor modified nonporous, porous, or microporous battery separatormembranes or separators for lithium ion batteries and/or related methodsof manufacture and/or use of such membranes or separators. In accordancewith at least selected particular embodiments, the present invention isdirected to improved, new or modified nonporous, porous, or microporousbattery separator membranes or separators for secondary or rechargeablelithium ion batteries and/or related methods of manufacture and/or useof such membranes or separators. In accordance with at least certainselected particular embodiments, the present invention is directed tononporous, porous, or microporous coated porous or microporous batteryseparator membranes or separators for secondary lithium ion batteriesand/or related methods of manufacture and/or use of such membranes orseparators. In accordance with at least one embodiment, an improved, newor modified nonporous, porous, or microporous membrane, separatormembrane or separator for a lithium ion battery includes a porous ormicroporous membrane coated with a ceramic coating or layer such as alayer of one or more particles and/or binders. In accordance with atleast one particular embodiment, an improved, new or modified nonporous,porous, or microporous membrane, separator membrane or separator for asecondary lithium ion battery includes a microporous membrane coatedwith at least one porous ceramic coating or layer such as a layer of oneor more ceramic particles and polymeric binders. In accordance with atleast selected embodiments, the inventive ceramic coated separatormembrane or separator preferably provides improved safety, cycle lifeand/or high temperature performance in a secondary lithium ion battery.

SUMMARY OF THE INVENTION

In accordance with at least selected embodiments, objects or aspects ofthe present invention, there is provided improved, new or modifiedmembranes, separators, and/or related methods. In accordance with atleast certain embodiments, the present invention is directed toimproved, new or modified nonporous, porous, or microporous batteryseparator membranes or separators and/or related methods of manufactureand/or use of such membranes or separators. In accordance with at leastselected embodiments, the present invention is directed to improved, newor modified nonporous, porous, or microporous battery separatormembranes or separators for lithium ion batteries and/or related methodsof manufacture and/or use of such membranes or separators. In accordancewith at least selected particular embodiments, the present invention isdirected to improved, new or modified nonporous, porous, or microporousbattery separator membranes or separators for secondary or rechargeablelithium ion batteries and/or related methods of manufacture and/or useof such membranes or separators. In accordance with at least certainselected particular embodiments, the present invention is directed tononporous, porous, or microporous coated porous or microporous batteryseparator membranes or separators for secondary lithium ion batteriesand/or related methods of manufacture and/or use of such membranes orseparators. In accordance with at least one embodiment, an improved, newor modified nonporous, porous, or microporous membrane, separatormembrane or separator for a lithium ion battery includes a porous ormicroporous membrane coated with a ceramic coating or layer such as alayer of one or more particles and/or binders. In accordance with atleast one particular embodiment, an improved, new or modified nonporous,porous, or microporous membrane, separator membrane or separator for asecondary lithium ion battery includes a microporous membrane coatedwith at least one porous ceramic coating or layer such as a layer of oneor more ceramic particles and polymeric binders. In accordance with atleast selected embodiments, the inventive ceramic coated separatormembrane or separator preferably provides improved safety, cycle lifeand/or high temperature performance in a secondary lithium ion battery.

In accordance with at least selected embodiments, the present inventionis directed to improved, new or modified microporous membranes,separators, and/or related methods. In accordance with at least certainembodiments, the present invention is directed to improved, new ormodified microporous battery separator membranes or separators and/orrelated methods of manufacture and/or use of such membranes orseparators. In accordance with at least selected certain embodiments,the present invention is directed to improved, new or modifiedmicroporous battery separator membranes or separators for lithium ionbatteries and/or related methods of manufacture and/or use of suchmembranes or separators. In accordance with at least selected particularembodiments, the present invention is directed to improved, new ormodified microporous battery separator membranes or separators forsecondary or rechargeable lithium ion batteries and/or related methodsof manufacture and/or use of such membranes or separators. In accordancewith at least certain selected particular embodiments, the presentinvention is directed to coated microporous battery separator membranesor separators for secondary lithium ion batteries and/or related methodsof manufacture and/or use of such membranes or separators. In accordancewith at least one embodiment, an improved, new or modified microporousmembrane, separator membrane or separator for a lithium ion batteryincludes a microporous membrane coated with at least one coating,particle coating, and/or ceramic coating or layer such as a layer of oneor more particles, ceramics, polymers and/or binders. In accordance withat least one particular embodiment, an improved, new or modifiedmicroporous membrane, separator membrane or separator for a secondarylithium ion battery includes a microporous membrane coated with at leastone porous ceramic coating or layer such as a layer of one or moreceramic particles and polymeric binders. In accordance with at leastselected embodiments, the inventive ceramic coated microporous separatormembrane preferably provides improved safety, cycle life and/or hightemperature performance in a secondary lithium ion battery.

In accordance with at least one embodiment, an improved, new or modifiedmembrane, separator membrane or separator for a lithium ion batteryincludes a microporous membrane coated with a material, particlecoating, and/or ceramic coating or layer such as layer of one or moretypes of ceramic particles and at least one polymeric binder. Inaccordance with at least selected embodiments, the inventive ceramiccoated separator membrane preferably provides improved safety, cyclelife and/or high temperature performance in a secondary lithium ionbattery. The improvement in the safety, cycle life and/or hightemperature performance of the coated and/or ceramic coated separatormembrane is believed mainly due to the coating or ceramic coating orlayer undergoing an oxidation or reduction reaction at the interface ofthe coated separator and electrodes in a lithium ion battery. Theformation of an oxidized or reduced interfacial layer between aseparator and a battery electrode prevents or stops further oxidation orreduction reactions from occurring and improves the safety, cycle lifeand/or the high temperature performance of a lithium ion battery. Inaddition, the safety, cycle life and high temperature performance of thecoated and/or ceramic coated separator membrane is improved due to itshigh dimensional stability at elevated temperatures. Furthermore, in atleast certain embodiments, this unique inventive ceramic coatedmicroporous separator membrane preferably evolves >2% volatilecomponents at ≥250 deg C.

In accordance with at least selected embodiments, the present inventionpreferably provides a coated separator membrane for a secondary lithiumion battery which is preferably made up of a microporous polyolefinsubstrate coated on at least one side with a coating, particle coating,and/or ceramic coating or layer of one or more polymers or binders,particles, and/or ceramic particles and at least one polymeric binder.These selected embodiments further provide a process for producing aseparator according to the present invention, the use of an inventiveseparator in a secondary lithium ion battery, and the like. Theseselected embodiments, also provide an inventive separator thatpreferably has the advantage of improved safety, cycle life, and/or hightemperature performance when used in a lithium ion battery. Thisimproved, new or modified membrane, membrane separator or separator fora lithium ion battery is preferably coated on at least one side with amixture of a ceramic particle or particles and one or more aqueous orwater based polymeric binders. The aqueous or water based bindercontained in the ceramic coating or layer may undergo an oxidation orreduction reaction at the interface of the coated separator andelectrodes in a lithium ion battery. Oxidation or reduction reactionscan occur during the formation stage of a lithium ion battery or duringthe charging and/or discharging stage of a lithium ion battery. Theoxidized or reduced interfacial layer may provide a barrier orsacrificial interfacial layer on the surface of the coated separatorthat can prevent or stop further oxidation or reduction reactions fromoccurring at the interface and improve the performance or cycle life ofa lithium ion battery.

The nonporous, porous or microporous coating, particle coating, and/orceramic coating can be applied to a porous, macroporous or microporousmembrane, film or separator membrane as a single or multiple layercoating or layer structure and as a single or double side coating. Atleast selected embodiments of the present invention comprise a single ordouble side coating or ceramic coating that is about 1-12 μm thick ormore, preferably about 2-12 μm thick, more preferably about 3-10 μmthick, and most preferably about 3-7 μm thick. Selected embodiments ofthe present invention may preferably be distinguished from prior coatedor ceramic coated battery separators in at least one of five ways: 1)the inventive ceramic coated microporous membrane has a MachineDirection (MD) shrinkage of <2% at 120 deg C. for one hour when testedin free state and a MD shrinkage of <3% at 130 deg C. for one hour whentested in free state, 2) the inventive ceramic coated microporousmembrane has a MD shrinkage of <1% at 150 deg C. when tested usingThermomechanical Analysis (TMA), 3) the inventive ceramic coatedmicroporous membrane has a transverse direction (TD) shrinkage <1% at150 deg C. when tested using e-TMA, 4) the inventive ceramic coatedmicroporous membrane evolves >2% volatile components at 250 deg C. whentested using Thermogravimetric Analysis (TGA), and/or 5) the coatingresults in a low increase in Gurley for the inventive ceramic coatedmicroporous membrane.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a Thermomechanical Analysis (TMA) thermogram representation ofInventive Examples Ex 1 through Ex 5 and two comparative samples CE 1and CE 2 with testing performed in the Machine Direction (MD) of themembranes.

FIG. 2 is a Thermomechanical Analysis (TMA) thermogram representation ofInventive Examples Ex 1 through Ex 4 and Comparative samples CE 1 and CE2 with testing performed in the Transverse Direction (TD) of themembrane.

FIG. 3 is a Thermogravimetric Analysis (TGA) thermogram representationof Inventive Examples Ex 3 and Ex 4 and Comparative examples CE 3 and CE4.

FIG. 4 is a schematic cross-section illustration of a single side coatedmembrane, separator membrane or separator.

FIG. 5 is a schematic cross-section illustration of a double side coatedmembrane, separator membrane or separator.

Various examples, embodiments or aspects of the invention are shown inthe drawings. It should be recognized that these figures are merelyillustrative of the principles of the present invention. Numerousadditional embodiments, examples, modifications, and adaptations thereofwill be described below and are readily apparent to those skilled in theart without departing from the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with at least selected embodiments, objects or aspects ofthe present invention, there is provided improved, new or modifiedmembranes, separators, and/or related methods. In accordance with atleast certain embodiments, the present invention is directed toimproved, new or modified nonporous, porous, or microporous batteryseparator membranes or separators and/or related methods of manufactureand/or use of such membranes or separators. In accordance with at leastselected embodiments, the present invention is directed to improved, newor modified nonporous, porous, or microporous battery separatormembranes or separators for lithium ion batteries and/or related methodsof manufacture and/or use of such membranes or separators. In accordancewith at least selected particular embodiments, the present invention isdirected to improved, new or modified nonporous, porous, or microporousbattery separator membranes or separators for secondary or rechargeablelithium ion batteries and/or related methods of manufacture and/or useof such membranes or separators. In accordance with at least certainselected particular embodiments, the present invention is directed tononporous, porous, or microporous coated porous or microporous batteryseparator membranes or separators for secondary lithium ion batteriesand/or related methods of manufacture and/or use of such membranes orseparators. In accordance with at least one embodiment, an improved, newor modified nonporous, porous, or microporous membrane, separatormembrane or separator for a lithium ion battery includes a porous ormicroporous membrane coated with a ceramic coating or layer such as alayer of one or more particles and/or binders. In accordance with atleast one particular embodiment, an improved, new or modified nonporous,porous, or microporous membrane, separator membrane or separator for asecondary lithium ion battery includes a microporous membrane coatedwith at least one porous ceramic coating or layer such as a layer of oneor more ceramic particles and polymeric binders. In accordance with atleast selected embodiments, the inventive ceramic coated separatormembrane or separator preferably provides improved safety, cycle lifeand/or high temperature performance in a secondary lithium ion battery.

In accordance with at least selected embodiments, the present inventionis directed to improved, new or modified microporous membranes,separators, and/or related methods. In accordance with at least certainembodiments, the present invention is directed to improved, new ormodified microporous battery separator membranes or separators and/orrelated methods of manufacture and/or use of such membranes orseparators. In accordance with at least selected certain embodiments,the present invention is directed to improved, new or modifiedmicroporous battery separator membranes or separators for lithium ionbatteries and/or related methods of manufacture and/or use of suchmembranes or separators. In accordance with at least selected particularembodiments, the present invention is directed to improved, new ormodified microporous battery separator membranes or separators forsecondary or rechargeable lithium ion batteries and/or related methodsof manufacture and/or use of such membranes or separators. In accordancewith at least certain selected particular embodiments, the presentinvention is directed to coated microporous battery separator membranesor separators for secondary lithium ion batteries and/or related methodsof manufacture and/or use of such membranes or separators. In accordancewith at least one embodiment, an improved, new or modified microporousmembrane, separator membrane or separator for a lithium ion batteryincludes a microporous membrane coated with at least one coating,particle coating, and/or ceramic coating or layer such as a layer of oneor more particles, ceramics, polymers and/or binders. In accordance withat least one particular embodiment, an improved, new or modifiedmicroporous membrane, separator membrane or separator for a secondarylithium ion battery includes a microporous membrane coated with at leastone porous ceramic coating or layer such as a layer of one or moreceramic particles and polymeric binders. In accordance with at leastselected embodiments, the inventive ceramic coated microporous separatormembrane preferably provides improved safety, cycle life and/or hightemperature performance in a secondary lithium ion battery.

In accordance with at least one embodiment, an improved, new or modifiedmembrane, separator membrane or separator for a lithium ion batteryincludes a microporous membrane coated with a material, particlecoating, and/or ceramic coating or layer such as layer of one or moretypes of ceramic particles and at least one polymeric binder. Inaccordance with at least selected embodiments, the inventive ceramiccoated separator membrane preferably provides improved safety, cyclelife and/or high temperature performance in a secondary lithium ionbattery. The improvement in the safety, cycle life and/or hightemperature performance of the coated and/or ceramic coated separatormembrane is believed mainly due to the coating or ceramic coating orlayer undergoing an oxidation or reduction reaction at the interface ofthe coated separator and electrodes in a lithium ion battery. Theformation of an oxidized or reduced interfacial layer between aseparator and a battery electrode prevents or stops further oxidation orreduction reactions from occurring and improves the safety, cycle lifeand/or the high temperature performance of a lithium ion battery. Inaddition, the safety, cycle life and high temperature performance of thecoated and/or ceramic coated separator membrane is improved due to itshigh dimensional stability at elevated temperatures. Furthermore, in atleast certain embodiments, this unique inventive ceramic coatedmicroporous separator membrane preferably evolves >2% volatilecomponents at ≥250 deg C.

In accordance with at least selected embodiments, the present inventionpreferably provides a coated separator membrane for a secondary lithiumion battery which is preferably made up of a microporous polyolefinsubstrate coated on at least one side with a coating, particle coating,and/or ceramic coating or layer of one or more polymers or binders,particles, and/or ceramic particles and at least one polymeric binder.These selected embodiments further provide a process for producing aseparator according to the present invention, the use of an inventiveseparator in a secondary lithium ion battery, and the like. Theseselected embodiments, also provide an inventive separator thatpreferably has the advantage of improved safety, cycle life, and/or hightemperature performance when used in a lithium ion battery. Thisimproved, new or modified membrane, membrane separator or separator fora lithium ion battery is preferably coated on at least one side with amixture of a ceramic particle or particles and one or more aqueous orwater based polymeric binders. The aqueous or water based bindercontained in the ceramic coating or layer may undergo an oxidation orreduction reaction at the interface of the coated separator andelectrodes in a lithium ion battery. Oxidation or reduction reactionscan occur during the formation stage of a lithium ion battery or duringthe charging and/or discharging stage of a lithium ion battery. Theoxidized or reduced interfacial layer may provide a barrier orsacrificial interfacial layer on the surface of the coated separatorthat can prevent or stop further oxidation or reduction reactions fromoccurring at the interface and improve the performance or cycle life ofa lithium ion battery.

The nonporous, porous or microporous coating, particle coating, and/orceramic coating can be applied to a porous, macroporous or microporousmembrane, film or separator membrane as a single or multiple layercoating or layer structure and as a single or double side coating. Atleast selected embodiments of the present invention comprise a single ordouble side coating or ceramic coating that is about 1-12 μm thick ormore, preferably about 2-12 μm thick, more preferably about 3-10 μmthick, and most preferably about 3-7 μm thick. Selected embodiments ofthe present invention may preferably be distinguished from prior coatedor ceramic coated battery separators in at least one of five ways: 1)the inventive ceramic coated microporous membrane has a MachineDirection (MD) shrinkage of <2% at 120 deg C. for one hour when testedin free state and a MD shrinkage of <3% at 130 deg C. for one hour whentested in free state, 2) the inventive ceramic coated microporousmembrane has a MD shrinkage of <1% at 150 deg C. when tested usingThermomechanical Analysis (TMA), 3) the inventive ceramic coatedmicroporous membrane has a transverse direction (TD) shrinkage <1% at150 deg C. when tested using e-TMA, 4) the inventive ceramic coatedmicroporous membrane evolves >2% volatile components at 250 deg C. whentested using Thermogravimetric Analysis (TGA), and/or 5) the coatingresults in a low increase in Gurley for the inventive ceramic coatedmicroporous membrane.

The present invention is preferably directed to improved, new ormodified battery separators, and/or related methods. In accordance withat least certain embodiments, the present invention is directed toimproved, new or modified nonporous, porous or microporous batteryseparators and/or related methods of manufacture and/or use of suchseparators. In accordance with at least selected embodiments, thepresent invention is directed to improved, new or modified coated,particle coated or ceramic coated battery separators for lithium ionbatteries and/or related methods of manufacture and/or use of suchseparators. In accordance with at least selected particular embodiments,the present invention is directed to improved, new or modified coated,particle coated or ceramic coated battery separators for secondary orrechargeable lithium ion batteries and/or related methods of manufactureand/or use of such separators. In accordance with at least certainselected particular embodiments, the present invention is directed tocoated battery separators including a microporous membrane, film orseparator with a coating on at least one side thereof and/or relatedmethods of manufacture and/or use of such separators. In accordance withat least one embodiment, an improved, new or modified coated separatorfor a lithium ion battery includes a microporous membrane coated with aceramic coating or layer such as porous or nonporous layer of ceramicparticles and at least one polymeric binder. In accordance with at leastselected embodiments, the inventive ceramic coated separator preferablyprovides improved safety, cycle life and/or high temperature performancein a secondary lithium ion battery.

In accordance with selected embodiments, the coating, particle coatingor ceramic coating may be present on one or both sides of the membrane,film, separator membrane or separator. FIGS. 4 and 5 show respectivesingle sided or single side coated and double sided or double sidecoated embodiments. It should be noted that in FIGS. 4 and 5 that thecoatings may be polymer, particle or ceramic coatings, that the coatingsmay be porous or non-porous, and that in the double side coatedembodiment of FIG. 5 that the coating may be the same or different oneach side. For example, although two ceramic coatings are shown, it isunderstood that one side may be a particle-free coating (such as PVDF),a particle coating (such as polymer particles in a binder), or a ceramiccoating (such as ceramic particles in a binder or polymeric binder) andthe other side may be the same or a different coating, particle coating,or ceramic coating. One side may be adapted to contact the cathode whilethe other side may be adapted to contact the anode. For instance, oneside may be PVDF coated while the other side is ceramic coated with amixture of a one or more ceramic particles combined with one or morepolymeric binders such as PP, PE, PO, PVDF or PTFE.

The preferred membrane, film, base layer, membrane separator orseparator may be a microporous polyolefin (PO) substrate that can bemade by a dry process (also know as the CELGARD process), wet process,particle stretch process, BOPP process, BNBOPP process, or the like. Thedry process refers to a process where the pore formation in amicroporous membrane results from uniaxial or biaxial stretching of anonporous precursor membrane (annular or slot die extrusion). The wetprocess typically involves a thermally induced phase separation processand a solvent extraction step (or TIPS process). The membrane, film,base layer, separator membrane or separator may preferably be a singlelayer (monolayer) or a multilayer (such as bi-layer or tri-layer orother multi-layer) microporous polyolefin membrane having or consistingof two or more layers of the same or dissimilar polyolefins. Exemplarypolyolefins include, but are not limited to, polypropylene (PP),polyethylene (PE), polymethyl pentene (PMP) copolymers of any of theforegoing and mixtures thereof. The preferred microporous polyolefinsubstrate has a thickness ranging from about 1-100 μm, preferably about4-50 μm, more preferably about 6-30 μm, and most preferably 8-20 μm. Thepreferred membranes are Celgard® brand membranes available from Celgard,LLC of Charlotte, N.C.

The ceramic coating is preferably made up of, includes or is comprisedof one or more ceramic particles or materials mixed with one or moreaqueous or water based binders, polymers, polymeric binders, or thelike. The ceramic particles may be inorganic or organic, preferablyinorganic. Non-limiting exemplary examples of inorganic particles areoxides of silicon (SiO₂), alumina (Al₂O₃), zirconium, titanium (TiO₂) orzinc or mixtures thereof or carbonates of silicon, alumina, zirconium,calcium, zinc, and blends or mixtures thereof. A preferred particle isAl₂O₃. The inorganic particles may have an average particle size rangingfrom 0.05 to 5 μm in diameter, more preferably 0.01 to 4 μm in diameterand most preferably 0.01 to 2 μm in diameter. The ceramic particles arepreferably adapted to keep the electrodes spaced apart or separated athigh temperatures given sufficient loading of particles and coatingthickness or add.

The particle coating is preferably made up of, includes or is comprisedof one or more particles or materials mixed with one or more aqueous orwater based binders, polymeric binders, polymers, or the like. Theparticles may be inorganic or organic, preferably organic. Non-limitingexemplary examples of organic particles are polymer materials orparticles, such as polymer fibers, beads, chips, or the like. Preferredpolymers may include PP, PE, PO, PP/PE, PET, PTFE, PVDF, copolymers,block copolymers, or blends or mixtures thereof. A preferred particle isPO, PVDF or PET. The organic particles may have an average particle sizeranging from 0.05 to 5 μm in diameter, more preferably 0.01 to 4 μm indiameter, and most preferably 0.01 to 2 μm in diameter. Certain hightemperature polymer particles may preferably be adapted to keep theelectrodes spaced apart or separated at high temperatures givensufficient loading of particles and coating thickness or add.

The preferred water based polymeric binder can be polyvinyl alcohol(PVOH), polyvinyl acetate (PVAc), polyacrylic acid salt,polyacrylonitrile, polyacrylamide or poly (sodiumacrylate-acrylamide-acrylonitrile) copolymer or copolymers of the aboveor blends or mixtures of the above.

The polymeric binder: ceramic particle ratio comprising the coatingmixture may be from 1:99 to 99:1.

Methods for coating a microporous polyolefin substrate include anyconventional coating manner such as dip coating, gravure coating, spraycoating, electrospin or electrospun coating, myer rod dip coating, slotdie or extrusion coating, sputtering, vapor deposition, sputteringchemical vapor deposition, or the like. The ceramic coating can beapplied to a microporous membrane, substrate or separator membrane as asingle or double side coating. At least selected embodiments of thepresent invention comprise a single or double side ceramic coating thatis preferably about 2-12 μm thick, more preferably about 3-10 μm thick,and most preferably 3-7 μm thick. The preferred method is a double sidecoating.

The possibly preferred inventive ceramic coated microporous separatormembrane has improved high temperature stability due to a reduction inthe amount of machine direction and transverse direction shrinkage ofthe membrane at elevated temperatures. The inventive ceramic coatedseparator membrane was analyzed using a TA Instrument ThermomechanicalAnalyzer model TMA Q400. In this test method, a sample 5 mm in lengthand 5.9 mm in width is held under a constant load of 0.02N while thetemperature is ramped up at 5° C./min rate until the temperature exceedsthe melting point of the sample and the sample ruptures. Typically, asthe temperature of a separator membrane sample is increased, the sampleinitially shows small but a measurable amount of shrinkage followed byelongation of the sample until it eventually breaks or ruptures. Theinitial shrinkage exhibited by the separator membrane film is defined asstrain shrinkage. The temperature at the point of break or rupture ofthe sample is defined as the rupture temperature.

FIG. 1 shows a thermogram analysis or TMA analysis with the sample inthe MD direction for inventive examples Ex 1 through Ex 5, together withthe comparative examples CE 1 and CE 2. TMA data for the ceramic coatedsamples Ex 1, Ex 2 and Ex 3 shows a marked reduction in the amount of MDstrain shrinkage for the ceramic coated PE samples between 90 and 130deg C. as compared to the uncoated CE 1 control. Inventive Ex 4, aceramic coated PP/PE/PP trilayer membrane Celgard C-210, also shows areduction in the amount for strain shrinkage compared to the uncoatedcontrol sample CE 2. Furthermore, the MD strain shrinkage of Ex 5, amonolayer PP ceramic coated microporous membrane is reduced. Theinventive ceramic coating produces a reduction in the amount of MDstrain shrinkage of the PE, PP and multilayer microporous separatormembranes containing PP and PE at temperatures between 90 and 130 deg C.

At a temperature of 130 deg C., the TMA MD direction shrinkage of Ex 1through Ex 5 is shown to be <2%. Furthermore, at 140 deg C., the TMA MDdirection strain shrinkage of ceramic coated PE microporous membraneshown in Ex 1, Ex 2 and Ex 3 is <2%. Furthermore, at 150 deg C., the TMAMD direction strain shrinkage of ceramic coated PE microporous membraneEx 1, Ex 2 and Ex 3 is <2%. Furthermore, at 160 deg C., the TMA MDdirection strain shrinkage of ceramic coated PE microporous membrane Ex2 and Ex 3 is <2%.

Furthermore, the TMA test results in the MD direction shows that a totalceramic coating thickness of 5-6 um (see Ex 2 in FIG. 1) when applied asa double sided coating to the PE membrane is sufficient to prevent theceramic coated PE separator membrane from melting up to 250 deg C.

FIG. 2 shows TMA test results in the transverse direction (TD) onsamples Ex 1 through Ex 5 and Comparative examples CE 1 and CE 2. Theinventive ceramic coating has a very low TD strain shrinkage of <1%. Ex2 has high temperature stability up to a temperature of 225 deg C.

One preferred beneficial effect of the inventive ceramic coated batteryseparator membrane in a lithium ion battery is improved safetyperformance at high temperatures.

A minimal amount of MD and TD strain shrinkage of the separator atelevated temperatures may be a key factor in maintaining an insulating,electrically nonconductive barrier to prevent any contact between thebattery anode and cathode.

FIG. 3 shows a Thermogravimetric Analysis (TGA) thermogram for theinventive ceramic coated separator membrane Ex 3 and Ex 4 together withcomparative patent examples CE 3 and CE 4. TGA analysis of the inventiveceramic coated separator was performed using TA Instruments TGA Q50model to monitor the change in the mass of the inventive ceramic coatedseparator membrane as a function of increasing temperature.

TGA is a process that utilizes heat and stoichiometry ratios todetermine the percent by mass of a solute in a sample. TGA can quantifyloss of volatile components in a test sample.

CE 3 and CE 4 show <1.4% weight loss by a temperature of 250 deg C. Incontrast, the inventive ceramic coated separator membrane samples Ex 3and Ex 4 exhibit a loss of volatile components of >2% by weight at atemperature of 250 deg C. The inventive ceramic coated separatormembranes in FIG. 3 were used to make lithium ion batteries thatunderwent a total of 400 charge/discharge cycles at a temperature of 45deg C. The ceramic coated separator membrane Ex 3 and Ex 4 were removedfrom the batteries after the 400 cycle testing and a TGA performed onthe ceramic coated separator membranes. Ex 3 and Ex 4 show greater than90% retention in mass after 400 battery cycles which meets industrialbattery cycling standards.

Test Methods

Shrinkage is measured at 120 deg C. for one hour or at 130 deg C. forone hour using modified ASTM 2732-96 procedure. Both the width andlength of a sample are measured before and after heat treatment. Samplesare placed in an oven in a free state meaning the sample is not placedunder tension and the sample is not supported by a tentering frame. Thenet shrinkage is calculated by the following formula:

% Net shrinkage=100*(Lo−L1)/(Lo+(Wo−W1/Wo))

Where Lo is the length of the sample before treatment, L1 is the lengthof the sample after treatment, Wo is the width of the sample beforetreatment and W1 is the width of the sample after treatment.

Gurley is defined as the Japanese Industrial Standard (JIS Gurley) andis a gas permeability test measured using the OHKEN permeability tester.JIS Gurley is the time in seconds required for 100c of air to passthrough one square inch of film at a constant pressure of 4.8 inches ofwater.

Thickness is measured in micrometers, pm, using the Emveco Microgage210-A micrometer thickness tester and test procedure ASTM D374.

Thermomechanical Analysis (TMA) involves measuring the shape change of asample under load, while the temperature is linearly increased. TAInstruments TMA Q400 was used for the analysis. The TMA analytical testutilizes a small separator sample 5 mm in length and 5.9 mm in widththat is held in mini-Instron type grips. The sample is held underconstant tension or load of approximately 0.02N while the temperature isramped at 5° C./min until the temperature exceeds the melting point ofthe sample and the sample ruptures at the rupture temperature. Typicallyas the temperature of a separator membrane sample is increased, thesample initially show some shrinkage and then starts to elongate untilthe sample eventually breaks or ruptures. The initial shrinkageexhibited by the separator membrane film is defined as strain shrinkage.

Thermogravimetric Analysis (TGA) is a technique in which the mass of asubstance is monitored as a function of temperature or time as thesample specimen is subjected to a controlled temperature program in acontrolled atmosphere. TA Instruments TGA Q50 model was used for theanalysis. TGA is a process that utilizes heat and stoichiometry ratiosto determine the percent by mass of a solute contained in a sample.Analysis is carried out by raising the temperature of the samplegradually and plotting weight (percentage) against temperature. TGA canquantify loss of water, loss of solvent, loss of plasticizer,decarboxylation, pyrolysis, oxidation, decomposition, weight % filler,amount of metallic catalytic residue remaining on carbon nanotubes, andweight % ash.

In accordance with at least selected embodiments, it may be preferred touse Thin or Ultra-Thin separators, Thin or Ultra-Thin separators withshutdown, Thin or Ultra-Thin tri-layer separators with shutdownbehavior, or the like. In one embodiment, the use of battery separatorsin the Thin range of about 9 to 12 microns or in the Ultra-Thin range ofabout 3 to 9 microns which retain the ability to shutdown is preferred.Also, it may be preferred to use a PP/PE/PP tri-layer configuration inwhich the PP layer thickness is less than 20 microns, less than 10microns, less than 5 microns, less than 2.5 microns, or between about0.5 micron and 1.5 microns. In accordance with at least selectedparticular embodiments, it may be preferred to use a PP/PE/PP orPP/PP/PP or PP/PE/PE or PP/PP/PE tri-layer battery separatorconstruction with product thicknesses ranging from about 6 μm to 80 μmwherein the outermost PP layer thicknesses is less than 20 μm, less than10 μm, less than 5 μm, less than 2.5 μm, or between about 0.25 μm and 2μm.

EXAMPLES Example 1

Celgard® EK1240 Polyethylene (PE) 12 μm microporous separator membranewas coated with a mixture of an aqueous polymeric binder consisting of acopolymer of polysodium acrylate, acrylamide and acrylonitrile combinedwith Degussa Al₂O₃ ceramic particles with average particle size is <2um. The coating was double side coated with total coating thickness of 4um. The final coated membrane thickness was 16 μm as shown in Table 1.

TABLE 1 Base Coated Exam- membrane Coated Membrane ple Base thickness,Membrane thickness, # membrane μm Manufacturer μm Ex 1 Celgard ® 12Celgard 16 EK1240 Ex 2 Celgard ® 12 Celgard 18 EK1240 Ex 3 Celgard ® 13Celgard 20 EK1311 Ex 4 Celgard ® C-210 16 Celgard 22 Ex 5 Celgard ® A27318 Celgard 22 CE1 Celgard ® 12 uncoated na EK1240 CE 2 Celgard ® C210 16uncoated na CE 3 Celgard ® 2320 16 Company A 28 CE 4 Monolayer PE 26Company B 33

Example 2

Celgard® EK1240 Polyethylene (PE) 12 μm microporous separator membranewas coated with a mixture of an aqueous polymeric binder consisting of acopolymer of polysodium acrylate, acrylamide and acrylonitrile combinedwith Degussa Al₂O₃ ceramic particles with average particle size is <2um. The coating was double side coated with total coating thickness of 6um. Final coated membrane thickness was 18 μm.

Example 3

Celgard® EK1311 Polyethylene (PE) 13 μm microporous separator membranewas coated with a mixture of an aqueous polymeric binder consisting of acopolymer of polysodium acrylate, acrylamide and acrylonitrile combinedwith Degussa Al₂O₃ ceramic particles with average particle size is <2μm. The coating was double side coated with total coating thickness of 7um. Final coated membrane thickness was 20 μm.

Example 4

Celgard® C210 Polypropylene/Polyethylene/Polypropylene (PP/PE/PP) 16 μmtrilayer microporous separator membrane was coated with a mixture of anaqueous polymeric binder consisting of a copolymer of polysodiumacrylate, acrylamide and acrylonitrile combined with Degussa Al₂O₃ceramic particles with average particle size is <2 μm. The coating wasdouble side coated with total coating thickness of 6 um. Final coatedmembrane thickness was 22 μm.

Example 5

Celgard® A273 Polypropylene (PP) 16 μm microporous separator membranewas coated with a mixture of an aqueous polymeric binder consisting of acopolymer of polysodium acrylate, acrylamide and acrylonitrile combinedwith Degussa Al₂O₃ ceramic particles with average particle size is <2μm. The coating was double side coated with total coating thickness of 6um. Final coated membrane thickness was 22 μm.

Comparative Example 1

Celgard® EK1240, manufactured by Celgard Korea Inc, is a 12 μm thickuncoated monolayer Polyethylene (PE) microporous separator membrane.

Comparative Example 2

Celgard® C-210 is a 16 μm thick uncoated trilayerPolypropylene/Polyethylene/Polypropylene (PP/PE/PP) microporousseparator membrane.

Comparative Example 3

Comparative Example 3 is a coated product manufactured by Company Ausing Celgard® 2320 as the microporous base substrate membrane. Thecoating consists of a mixture of ceramic particles and a polymericbinder which is double side coated with a coating thickness of 33.5 μm.

Comparative Example 4

Comparative Example 4 is a PE microporous separator membranemanufactured by Company B which is single side coated with a mixture ofa ceramic particles and a polymeric binder and has a coating thicknessof 33 μm.

At least one embodiment, object or aspect of the present invention isdirected to an improved, new or modified microporous membrane separatorfor a secondary lithium ion battery which includes a microporousmembrane coated with a porous layer of ceramic particles and a polymericbinder. This inventive ceramic coated microporous separator membrane hasimproved safety and high temperature performance in a secondary lithiumion battery mainly due to the ceramic coating layer undergoing anoxidation or reduction reaction at the interface of the coated separatorand battery electrodes. The formation of an oxidized or reducedinterfacial layer between a separator and battery electrodes prevents orstops further oxidation or reduction reactions from occurring andimproves the safety and the high temperature performance of a lithiumion battery. In addition, the safety and high temperature performance ofthe ceramic coated microporous separator membrane is improved due to itshigh dimensional stability at elevated temperatures. Furthermore, thisunique ceramic coated microporous separator membrane evolves >2%volatile components at >250 deg C.

At least one embodiment, object or aspect of the present invention isdirected to a ceramic coated separator for a secondary lithium ionbattery, comprising:

-   -   a. a microporous membrane having a first surface and a second        surface, wherein said microporous membrane is at least one of a        single layer, multiple layer, single ply, and/or multiple ply        structure; and,    -   b. a porous ceramic coating on at least one surface of said        microporous membrane, said porous ceramic coating comprising a        porous layer of ceramic particles in an aqueous polymeric        binder, and wherein said porous ceramic coating provides an        oxidation scavenging layer which prevents or stops further        oxidation or reduction reactions from occurring during use.

In accordance with at least selected embodiments, objects or aspects ofthe present invention, there is provided improved, new or modifiedmembranes, separators, and/or related methods. In accordance with atleast certain embodiments, the present invention is directed toimproved, new or modified nonporous, porous, or microporous batteryseparator membranes or separators and/or related methods of manufactureand/or use of such membranes or separators. In accordance with at leastselected embodiments, the present invention is directed to improved, newor modified nonporous, porous, or microporous battery separatormembranes or separators for lithium ion batteries and/or related methodsof manufacture and/or use of such membranes or separators. In accordancewith at least selected particular embodiments, the present invention isdirected to improved, new or modified nonporous, porous, or microporousbattery separator membranes or separators for secondary or rechargeablelithium ion batteries and/or related methods of manufacture and/or useof such membranes or separators. In accordance with at least certainselected particular embodiments, the present invention is directed tononporous, porous, or microporous coated porous or microporous batteryseparator membranes or separators for secondary lithium ion batteriesand/or related methods of manufacture and/or use of such membranes orseparators. In accordance with at least one embodiment, an improved, newor modified nonporous, porous, or microporous membrane, separatormembrane or separator for a lithium ion battery includes a porous ormicroporous membrane coated with a ceramic coating or layer such as alayer of one or more particles and/or binders. In accordance with atleast one particular embodiment, an improved, new or modified nonporous,porous, or microporous membrane, separator membrane or separator for asecondary lithium ion battery includes a microporous membrane coatedwith at least one porous ceramic coating or layer such as a layer of oneor more ceramic particles and polymeric binders. In accordance with atleast selected embodiments, the inventive ceramic coated separatormembrane or separator preferably provides improved safety, cycle lifeand/or high temperature performance in a secondary lithium ion battery.

In accordance with selected objects, improved, new or modifiedmembranes, separators, and/or related methods are provided. Inaccordance with at least certain objects, improved, new or modifiedbattery separator membranes or separators and/or related methods ofmanufacture and/or use of such membranes or separators are provided. Inaccordance with at least certain selected particular objects, coatedbattery separator membranes or separators for secondary lithium ionbatteries and/or related methods of manufacture and/or use of suchmembranes or separators are provided.

In a further aspect, methods of making improved, new or modifiedmembranes, separators, and/or related products are described herein. Onemethod of making a coated membrane or separator, in some embodiments,comprises dispersing inorganic particles in a polymeric matrix or bindermaterial to provide a composite coating or layer material and formingthe coating or layer on a preformed base membrane or separator from thecomposite coating material.

The membrane or separator can be formed in any manner not inconsistentwith the objectives of the present invention, including in a mannerdescribed above. In some embodiments, for instance, a composite membraneor separator may be formed by lamination, extrusion, co-extrusion, spraycoating, roller coating, dry extrusion, wet extrusion, and/or the like.Any extrusion equipment not inconsistent with the objectives of thepresent invention may be used to carry out such a method describedherein. In some cases, for example, a single or twin-screw extruder isused. In addition, if desired, the base membrane described herein can beformed using a die process, including a slot or annular die process,cast or blown, or the like.

In addition, any amount of particles, inorganic particles, organicparticles, or a blend or mixture thereof not inconsistent with theobjectives of the present invention may be used to provide the desiredcoating material or layer. In some cases, up to about 98 weight percentinorganic and/or organic particles, up to about 80 weight percentinorganic and/or organic particles, up to about 60 weight percentinorganic and/or organic particles, up to about 50 weight percentinorganic and/or organic particles, or up to about 40 weight percentinorganic and/or organic particles is used to provide the particlecomponent for the coating material, wherein the weight percent is basedon the total weight of the composite coating material.

A composite membrane produced in accordance with methods describedherein can have any construction and/or properties detailed above. Forexample, in some embodiments, a composite membrane produced inaccordance with methods described herein comprises a plurality ofpolymeric layers, wherein at least one layer comprises a microporouspolymeric matrix comprising inorganic and/or organic particles dispersedin the polymeric matrix or binder as described herein. In someembodiments, more than one individual layer of the composite membranecomprises inorganic and/or organic particles. Alternatively, in otherembodiments, only one individual layer of the composite membranecomprises inorganic and/or organic particles.

In accordance with at least selected possibly preferred embodiments ofthe invention, there is provided a ceramic coated separator for anenergy storage device, such as a secondary lithium ion battery,comprising:

-   -   a. a microporous membrane having a first surface and a second        surface, wherein said microporous membrane is at least one of a        single layer, multiple layer, single ply, and/or multiple ply        structure; and,    -   b. a ceramic coating on at least one surface of said microporous        membrane, said ceramic coating comprising a porous layer of        ceramic particles in an aqueous polymeric binder,

wherein said ceramic coated separator provides at least one of improvedsafety, high temperature performance, an oxidation or reduction reactioninterface, surface or boundary, an oxidized or reduced interfacial layerbetween the separator and battery electrodes during use, prevents orstops further oxidation or reduction reactions from occurring duringuse, improved safety and high temperature performance of a lithium ionbattery, high dimensional stability at elevated temperatures, and/or thelike.

The above ceramic coated separator, wherein said aqueous polymericbinder comprises at least one of polytetrafluoroethylene (PTFE),polyvinyl acetate (PVAc), polyacrylic acid salt, polyacrylonitrile,polyacrylamide or poly (sodium acrylate-acrylamide-acrylonitrile)copolymer, and/or copolymers, mixtures, blends, and/or combinationsthereof.

The above ceramic coated separator, wherein said aqueous polymericbinder comprises at least two of polyvinyl alcohol (PVOH), polyvinylacetate (PVAc), polyacrylic acid salt, polyacrylonitrile, polyacrylamideor poly (sodium acrylate-acrylamide-acrylonitrile) copolymer orcopolymers thereof.

The above ceramic coated separator, wherein said ceramic particlescomprise at least one of inorganic particles, ionically conductivematerials (beta-Alumina, Nasicon which is a sodium super ionicconductive material, phosphates of Silica and Al), oxides of silicon(SiO₂), alumina (Al₂O₃), zirconium, titanium (TiO₂), mixtures thereof,or nitrides of silicon, alumina, zirconium, calcium, or mixturesthereof, and/or mixtures, blends and/or combinations thereof.

The above ceramic coated separator, wherein said ceramic particlescomprise particles having an average particle size ranging from 0.01 μmto 5 μm in diameter, more preferably 0.05 μm to 4 μm in diameter, andmost preferably 0.01 μm to 2 μm in diameter.

The above ceramic coated separator, wherein said ceramic particlescomprise Al₂O₃ having an average particle size ranging from 0.01 μm to 5μm in diameter, more preferably 0.05 μm to 4 μm in diameter, and mostpreferably 0.05 μm to 2 μm in diameter.

The above ceramic coated separator, wherein said porous ceramic coatingon at least one surface of said microporous membrane has a thickness ofabout 1.5 μm to 5.5 um.

The above ceramic coated separator, wherein said porous ceramic coatingon at least one surface of said microporous membrane has a thickness ofabout 1.5 μm to 5.5 μm, and wherein said ceramic coated separator has aTMA MD dimensional change of −2% or more at ≤110 deg C., preferably at≤130 deg C., more preferably at ≤140 deg C., even more preferably at≤160 deg C., and most preferably at ≤175 deg C.

The above ceramic coated separator, wherein said ceramic coatedseparator has a TMA TD shrinkage of about 0.5% or less ≤130 deg C.,preferably at ≤140 deg C., more preferably at ≤150 deg C., and mostpreferably at ≤160 deg C.

The above ceramic coated separator, wherein said porous ceramic coatingon at least one surface of said microporous membrane has a thickness ofabout 3.0 μm to 5.5 μm, and wherein said ceramic coated separator has anMD shrinkage of 15% or less at 135 deg C. for one hour, and preferablyan MD shrinkage of 28% or less at 150 deg C. for one hour.

The above ceramic coated separator, wherein said microporous membrane isa wet process polyethylene microporous membrane, wherein said porousceramic coating on at least one surface of said microporous membrane hasa thickness of about 3.0 μm to 5.5 μm, and wherein said ceramic coatedseparator has an MD shrinkage of 2% or less at 135 deg C. for one hour,and preferably an MD shrinkage of 5% or less at 150 deg C. for one hour.

The above ceramic coated separator, wherein said porous ceramic coatingon at least one surface of said microporous membrane has a thickness ofabout 3.0 μm to 5.5 μm, and wherein said ceramic coated separator has areduction in MD shrinkage at 135 deg C. for one hour of at least 40%over the uncoated membrane, preferably a reduction in MD shrinkage at150 deg C. for one hour of at least 30% over the uncoated membrane.

The above ceramic coated separator, wherein said microporous membrane isa wet process polyethylene microporous membrane, wherein said porousceramic coating on at least one surface of said microporous membrane hasa thickness of about 3.0 μm to 5.5 μm, and wherein said ceramic coatedseparator has a reduction in MD shrinkage at 135 deg C. for one hour ofat least 10% over the uncoated membrane, preferably a reduction in MDshrinkage at 150 deg C. for one hour of at least 5% over the uncoatedmembrane.

The above ceramic coated separator, wherein said porous ceramic coatingon at least one surface of said microporous membrane has a thickness ofabout 5.5 μm to 9.0 μm, and wherein said ceramic coated separator has anMD shrinkage of 4% or less at 135 deg C. for one hour, and preferably anMD shrinkage of 5% or less at 150 deg C. for one hour.

The above ceramic coated separator, wherein said microporous membrane isa wet process polyethylene microporous membrane, wherein said porousceramic coating on at least one surface of said microporous membrane hasa thickness of about 5.5 μm to 9.0 μm, and wherein said ceramic coatedseparator has an MD shrinkage of 2% or less at 135 deg C. for one hour,and preferably an MD shrinkage of 2% or less at 150 deg C. for one hour.

The above ceramic coated separator, wherein said porous ceramic coatingon at least one surface of said microporous membrane has a thickness ofabout 5.5 μm to 9.0 μm, and wherein said ceramic coated separator has areduction in MD shrinkage at 135 deg C. for one hour of at least 80%over the uncoated membrane, preferably a reduction in MD shrinkage at150 deg C. for one hour of at least 60% over the uncoated membrane.

The above ceramic coated separator, wherein said microporous membrane isa wet process polyethylene microporous membrane, wherein said porousceramic coating on at least one surface of said microporous membrane hasa thickness of about 5.5 μm to 9.0 μm, and wherein said ceramic coatedseparator has a reduction in MD shrinkage at 135 deg C. for one hour ofat least 90% over the uncoated membrane, preferably a reduction in MDshrinkage at 150 deg C. for one hour of at least 70% over the uncoatedmembrane.

The above ceramic coated separator, wherein said ceramic coatedseparator having aqueous binder and a scavenging filler such as Al2O3evolves ≥0.5% volatile components at >250 deg C., preferably >1.0%volatile components at ≥250 deg C., more preferably >1.5% volatilecomponents at >250 deg C., and most preferably ≥2.0% volatile componentsat >250 deg C.

The above ceramic coated separator, wherein said ceramic coatedseparator has a strain shrinkage of 0% at >120 deg C., preferablyat >130 deg C., more preferably at >140 deg C., still more preferablyat >150 deg C., and most preferably at ≥160 deg C.

The above ceramic coated separator, wherein said microporous membrane isa polyolefinic microporous membrane and has an MD stretch of less than20% at >120 deg C., preferably less than 15% at >120 deg C., morepreferably less than 10% at >120 deg C., still more preferably less than5% at >120 deg C., and most preferably less than 2% at >120 deg C.

In accordance with at least certain possibly preferred embodiments ofthe invention, there is provided in a secondary lithium ion battery, theimprovement comprising the ceramic coated separators described above.

In accordance with at least certain possibly preferred embodiments ofthe invention, there is provided in an electric vehicle drive system,the improvement comprising the above secondary lithium ion battery.

In accordance with at least certain possibly preferred embodiments ofthe invention, there is provided in an energy storage device, theimprovement comprising the above secondary lithium ion battery.

In accordance with at least certain selected possibly preferredembodiments of the invention, there is provided a ceramic coatedseparator for a secondary lithium ion battery, comprising:

-   -   c. a microporous membrane having a first surface and a second        surface, wherein said microporous membrane is at least one of a        single layer, multiple layer, single ply, and/or multiple ply        structure; and,    -   d. a porous ceramic coating on at least one surface of said        microporous membrane, said porous ceramic coating comprising a        porous layer of ceramic particles in an aqueous polymeric        binder, and wherein said porous ceramic coating provides an        oxidation scavenging layer which prevents or stops further        oxidation or reduction reactions from occurring during use.

The above ceramic coated separator, wherein said ceramic coatedseparator evolves >0.5% volatile components at >250 deg C.,preferably >1.0% volatile components at >250 deg C., morepreferably >1.5% volatile components at >250 deg C., and mostpreferably >2.0% or more volatile components at >250 deg C.

The above ceramic coated separator, wherein said microporous membrane isan Ultra-Thin tri-layer separator with shutdown behavior and is in theUltra-Thin range of about 3 to 9 microns with the ability to shut down.

In accordance with at least selected embodiments of the invention, thereis provided a coated, particle coated or ceramic coated separator for asecondary lithium ion battery, comprising:

-   -   a. a microporous membrane having a first surface and a second        surface, wherein said microporous membrane is at least one of a        single layer, multiple layer, single ply, and/or multiple ply        structure; and,    -   b. a non-porous or porous coating, particle coating or ceramic        coating on at least one surface of said microporous membrane,        said coating, particle coating or ceramic coating comprising a        non-porous or porous layer of polymeric binder, of particles in        a polymeric binder, or of ceramic particles in a solvent based        or aqueous based polymeric binder. Such a non-porous coating can        still be ionically conductive if, for example, the binder swells        and gels in electrolyte and is effectively ionically conductive        due to the electrolyte, the particles are ionically conductive        at least on their exterior surface, or both.

Various embodiments of the invention have been described in fulfillmentof the various objects of the invention. It should be recognized thatthese embodiments are merely illustrative of the principles of thepresent invention. Numerous modifications and adaptations thereof willbe readily apparent to those skilled in the art without departing fromthe spirit and scope of the invention.

1-29. (canceled)
 30. A ceramic-coated battery separator, comprising: amicroporous polyolefin membrane; and a ceramic coating on at least onesurface of said microporous polyolefin membrane, wherein theceramic-coated separator exhibits a strain shrinkage of 0% attemperatures greater than or equal to 120 degrees Celsius.
 31. Theceramic-coated separator of claim 30, wherein the ceramic-coatedseparator exhibits a strain shrinkage of 0% at temperatures greater thanor equal to 130 degrees Celsius.
 32. The ceramic-coated separator ofclaim 30, wherein the ceramic-coated separator exhibits a strainshrinkage of 0% at temperatures greater than or equal to 140 degreesCelsius.
 33. The ceramic-coated separator of claim 30, wherein theceramic-coated separator exhibits a strain shrinkage of 0% attemperatures greater than or equal to 160 degrees Celsius.
 34. Theceramic-coated separator of claim 30, wherein the ceramic coatingcomprises Al₂O₃.
 35. The ceramic-coated separator of claim 30, whereinthe ceramic coating comprises ceramic particles having an averageparticle size ranging from 0.01 microns to 5 microns.
 36. Theceramic-coated separator of claim 35, wherein the average particle sizeof the ceramic particles is from 0.05 microns to 2 microns.
 37. Theceramic-coated separator of claim 30, wherein the ceramic coating has athickness of 2 to 12 microns, 3 to 10 microns, or 3 to 7 microns. 38.The ceramic-coated separator of claim 30, wherein the microporouspolyolefin membrane is made by a dry process or a wet process.
 39. Theceramic-coated separator of claim 30, wherein the ceramic coating isformed using an aqueous or water-based binder.
 40. The ceramic-coatedseparator of claim 30, wherein the separator is a two-side coatedseparator.
 41. A ceramic-coated battery separator, comprising: amicroporous polyolefin membrane; and a ceramic coating on at least onesurface of said microporous polyolefin membrane, wherein at least one ofthe following is satisfied: the ceramic-coated separator exhibits aMachine Direction (MD) shrinkage of <2% at a temperature of greater thanor equal to 120 degrees C. for one hour when tested in free state and aMD shrinkage of <3% at a temperature of greater than or equal to 130degrees C. for one hour when tested in free state; the ceramic-coatedseparator exhibits a MD shrinkage of <1% at a temperature of greaterthan or equal to 150 degrees C. when tested using ThermomechanicalAnalysis (TMA); the ceramic-coated separator exhibits a transversedirection (TD) shrinkage of <1% at a temperature of greater than orequal to 150 degrees C. when tested using e-TMA; the ceramic-coatedseparator evolves >2% volatile components at 250 degrees C. when testedusing Thermogravimetric Analysis (TGA) and contains a scavenging fillerin the ceramic coating; and the ceramic coating results in a lowincrease in Gurley for the ceramic-coated microporous membrane comparedto the Gurley of the microporous membrane without the ceramic coating.42. The ceramic-coated separator of claim 41, wherein the ceramic-coatedseparator exhibits a Machine Direction (MD) shrinkage of <2% at atemperature greater than or equal to 120 degrees C. for one hour whentested in free state and a MD shrinkage of <3% at a temperature greaterthan or equal to 130 degrees C. for one hour when tested in free state.43. The ceramic-coated separator of claim 41, wherein the ceramic-coatedseparator exhibits a MD shrinkage of <1% at a temperature greater thanor equal to 150 degrees C. when tested using Thermomechanical Analysis(TMA).
 44. The ceramic-coated separator of claim 41, wherein theceramic-coated separator exhibits a transverse direction (TD) shrinkageof <1% at a temperature greater than or equal to 150 degrees C. whentested using e-TMA.
 45. The ceramic-coated separator of claim 41,wherein the ceramic-coated separator evolves >2% volatile components at250 degrees C. when tested using Thermogravimetric Analysis (TGA) andcontains a scavenging filler in the ceramic coating.
 46. Theceramic-coated separator of claim 41, wherein the ceramic coatingresults in a low increase in Gurley for the ceramic-coated microporousmembrane compared to the Gurley of the uncoated microporous membrane.47. The ceramic-coated separator of claim 41, wherein the ceramiccoating comprises Al₂O₃.
 48. The ceramic-coated separator of claim 41,wherein the microporous membrane is a membrane formed by a dry processor a wet process.
 49. The ceramic-coated separator of claim 41, whereinthe ceramic coating has a thickness of 2 to 12 microns, 3 to 10 microns,or 3 to 7 microns.
 50. The ceramic-coated separator of claim 41, whereinthe ceramic coating is formed using an aqueous or water-based binder.51. The ceramic-coated separator of claim 41, wherein the ceramiccoating comprises ceramic particles having an average particle sizeranging from 0.01 microns to 5 microns.
 52. The ceramic-coated separatorof claim 51, wherein the average particle size is from 0.05 microns to 2microns.
 53. The ceramic-coated separator of claim 30, furthercomprising a particle coating, which comprises organic particles,polymer fibers, polymer beads, or polymer chips, wherein the polymerincludes PP, PE, PO, PP/PE, PET, PTFE, PVDF, copolymers, blockcopolymers, or blends or mixtures thereof.
 54. The ceramic-coatedseparator of claim 41, further comprising a particle coating, whichcomprises organic particles, polymer fibers, polymer beads, or polymerchips, wherein the polymer includes PP, PE, PO, PP/PE, PET, PTFE, PVDF,copolymers, block copolymers, or blends or mixtures thereof.
 55. Theceramic-coated separator of claim 30, wherein the ceramic coatingcomprises a polymeric binder, which includes a copolymer of at least oneof a polyacrylic salt and a polyacrylamide.
 56. The ceramic-coatedseparator of claim 41, wherein the ceramic coating comprises a polymericbinder, which includes a copolymer of at least one of a polyacrylic acidsalt and a polyacrylamide.
 57. A ceramic-coated battery separator,comprising: a polyolefin wet-process microporous membrane; and a 3micron to 9 micron-thick ceramic coating on at least one surface of saidmicroporous membrane, wherein the ceramic-coated separator exhibits a MD(machine direction) shrinkage of 2% or less at a temperature greaterthan or equal to 135° C. for one hour.
 58. The ceramic-coated separatorof claim 57, wherein the separator exhibits a MD shrinkage of 5% or lessat a temperature greater than or equal to 150° C. for one hour.
 59. Acoated battery separator, comprising: a polyolefin microporous membrane;and a nonporous, porous, or microporous particle coating on at least onesurface of the membrane, wherein the particle coating comprises organicparticles, polymer fibers, polymer beads, or polymer chips, wherein thepolymer includes PP, PE, PO, PP/PE, PET, PTFE, PVDF, copolymers, blockcopolymers, or blends or mixtures thereof.